i guess everybody has that first moment where you go, oh, my god. >> nine years later, she's putting progress to canvas here. >> i really want to just be able to capture some of what's going on there. some of the change. >> in fact, ground zero is changing so quickly, that it's really hard for diana to keep her paintings up to date. >> this is a painting i've been working on for a month or so. >> and during that time, workers delivered the first trees to the site. >> now, i'm starting to put the trees in. >> they just came in. >> they just came in. >> you bring a little green today. >> exactly. >> for diana and todd, the change is a welcome relief. todd is going from painting a site filled with loss to a landscape bursting with hope. >> i've been painting what's not there. now, for the first time, there's the footprints of what's not there. it's been memorialized. for me, i feel like we've turned a corner. >> i'm done.